I do not understand your request; if you want to draw on the XY plane, the gray piece partially hides it, to no longer see the gray piece, you select it and kick the Spacebar (kick again to review)

Pouffes pouffes, je suis donc un manchot.

non ça te fais 2 mains gauche

you add material with a Pad:
I plug a round hole which is the original, and 2 hex in a safe way without TNP

Je dirais même plus, do a Mirror.

je pouff : you will have a left-hand thread

Do a LinearPattern

when you have sketches parallel to the General planes XY, XZ, YZ it is preferable to draw on these planes and move with the "Attachment" function
it's simpler than DatumPlan

the best can I do , in Part Wb only

this then : every line of the pyramid is tangent to the sphere (I think )

if it's good, I'll let SHLM explain to you

you make a pyramid by making a loft between a point at the top and a base square, then Thikness 8mm the choice of the vertex at the center of the axes is important for the rest the square is made on the XY plane and displacement with "attachment" the point of the vertex must be transformed...

I understand what you mean, it exists with Loft-Subtractive or Pipe-Subtractive: the removed part appears in pink before you click OK, except that it does not prevent an error if the result is a prohibited operation